The Study to Evaluate Patient Outcome Using Distal Protection Combined With the BX Velocity.

Inclusion Criteria: * Unstable angina pectoris (Braunwald classification B \& C, I-II-III, native vessels) * or lesion located in the SVG; * Single de novo or restenotic lesion requiring treatment in a major native coronary artery or saphenous vein graft; * The vessel diameter to place the AngioGuard™ device in must be \> 3 and \< 5.5 mm (6.5 when the 7mm AngioGuard™ is available); * Target lesion stenosis is \>50% and \<100% (TIMI 1). Exclusion Criteria: * A Q-wave or non-Q-wave myocardial infarction within the preceding 72 hours unless the CK and CK-MB enzymes are back to normal; * More than one coronary artery is 100% occluded; * Patient has unprotected left main coronary disease with \> 50% stenosis; * Patient has an ostial target lesion; * Significant (\>50%) untreated stenosis proximal or distal to the target lesion that will be treated during the procedure, since this may require revascularization or impede runoff; * Ejection fraction \<30%; * Totally occluded vessel (TIMI 0 Level).